#!/usr/bin/perl

my @box1 = (
   [ qw/a b c d e f g/ ],
   [ qw/h i j k l m n/ ],
   [ qw/o p q r s t u/ ],
);

my @box2 = (
   [ qw/01 02 03 04 05 06 07/ ],
   [ qw/20 21 22 23 24 25 08/ ],
   [ qw/19 32 33 34 35 26 09/ ],
   [ qw/18 31 30 29 28 27 10/ ],
   [ qw/17 16 15 14 13 12 11/ ],
);

my $iter1 = iterator( \@box1 );

while ( my $x = $iter1->() ) {
   print "$x ";
}

print "\n";

$iter2 = iterator( \@box2 );

while ( my $x = $iter2->() ) {
   print "$x ";
}

print "\n";